/*
* Copyright (c) 2011-2015 Spotify AB
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.spotify.asyncdatastoreclient;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;
import java.util.List;
import java.util.Objects;
import java.util.stream.Collectors;
/**
* Represents an entity key.
*
* A key is immutable; use {@code Key.builder()} to construct new
* {@code Key} instances.
*/
public final class Key {
/**
* Represents an key path element.
*
* A key path element is immutable.
*/
public static final class Element {
private final com.google.datastore.v1.Key.PathElement element;
private Element(final com.google.datastore.v1.Key.PathElement element) {
this.element = element;
}
public String getKind() {
return element.getKind();
}
public Long getId() {
return isId(element) ? element.getId() : null;
}
public String getName() {
return isName(element) ? element.getName() : null;
}
com.google.datastore.v1.Key.PathElement getPb() {
return element;
}
@Override
public String toString() {
final Long id = getId();
return getKind() + ":" + (id == null ? getName() : id);
}
}
private final com.google.datastore.v1.Key key;
private Key(final com.google.datastore.v1.Key key) {
this.key = key;
}
public static final class Builder {
private final com.google.datastore.v1.Key.Builder key;
private Builder() {
this.key = com.google.datastore.v1.Key.newBuilder();
}
private Builder(final Key key) {
this(key.getPb());
}
private Builder(final com.google.datastore.v1.Key key) {
this.key = com.google.datastore.v1.Key.newBuilder(key);
}
/**
* Creates a new {@code Key}.
*
* @return an immutable key.
*/
public Key build() {
return new Key(key.build());
}
/**
* Set the namespace for this {@code Key}.
*
* @param namespace the namespace to set.
* @return this key builder.
*/
public Builder namespace(final String namespace) {
key.setPartitionId(
com.google.datastore.v1.PartitionId.newBuilder().setNamespaceId(namespace));
return this;
}
/**
* Add a path element to this key.
*
* @param element the path element to add.
* @return this key builder.
*/
public Builder path(final Element element) {
key.addPath(element.getPb());
return this;
}
/**
* Add a path element of a given kind to this key.
*
* @param kind the path element kind.
* @return this key builder.
*/
public Builder path(final String kind) {
key.addPath(com.google.datastore.v1.Key.PathElement.newBuilder().setKind(kind));
return this;
}
/**
* Add a path element of a given kind and id to this key.
*
* @param kind the path element kind.
* @param id the path element id.
* @return this key builder.
*/
public Builder path(final String kind, final long id) {
key.addPath(com.google.datastore.v1.Key.PathElement.newBuilder().setKind(kind).setId(id));
return this;
}
/**
* Add a path element of a given kind and name to this key.
*
* @param kind the path element kind.
* @param name the path element name.
* @return this key builder.
*/
public Builder path(final String kind, final String name) {
key.addPath(com.google.datastore.v1.Key.PathElement.newBuilder().setKind(kind).setName(name));
return this;
}
/**
* Add a given key as a parent of this key.
*
* @param parent the parent key to add.
* @return this key builder.
*/
public Builder parent(final Key parent) {
for (final Element element : parent.getPath()) {
final Long id = element.getId();
final String name = element.getName();
if (id != null) {
path(element.getKind(), id);
} else if (name != null) {
path(element.getKind(), name);
}
}
return this;
}
}
/**
* Creates a new empty {@code Key} builder.
*
* @return an key builder.
*/
public static Key.Builder builder() {
return new Key.Builder();
}
/**
* Creates a new {@code Key} builder for a given kind.
*
* This is a shortcut for {@code Key.builder().path(kind).build()}
*
* @param kind the kind of entity key.
* @return a key builder.
*/
public static Key.Builder builder(final String kind) {
return new Key.Builder().path(kind);
}
/**
* Creates a new {@code Key} builder for a given kind with a parent.
*
* This is a shortcut for {@code Key.builder().parent(parent).path(kind).build()}
*
* @param kind the kind of entity key.
* @param parent the parent key to add.
* @return a key builder.
*/
public static Key.Builder builder(final String kind, final Key parent) {
return new Key.Builder().parent(parent).path(kind);
}
/**
* Creates a new {@code Key} builder for a given kind and an id.
*
* This is a shortcut for {@code Key.builder().path(kind, id).build()}
*
* @param kind the kind of entity key.
* @param id the id of entity key.
* @return a key builder.
*/
public static Key.Builder builder(final String kind, final long id) {
return new Key.Builder().path(kind, id);
}
/**
* Creates a new {@code Key} builder for a given kind and an id with a parent.
*
* This is a shortcut for {@code Key.builder().parent(parent).path(kind, id).build()}
*
* @param kind the kind of entity key.
* @param id the id of entity key.
* @param parent the parent key to add.
* @return a key builder.
*/
public static Key.Builder builder(final String kind, final long id, final Key parent) {
return new Key.Builder().parent(parent).path(kind, id);
}
/**
* Creates a new {@code Key} builder for a given kind and a name.
*
* This is a shortcut for {@code Key.builder().path(kind, name).build()}
*
* @param kind the kind of entity key.
* @param name the name of entity key.
* @return a key builder.
*/
public static Key.Builder builder(final String kind, final String name) {
return new Key.Builder().path(kind, name);
}
/**
* Creates a new {@code Key} builder for a given kind and an name with a parent.
*
* This is a shortcut for {@code Key.builder().parent(parent).path(kind, name).build()}
*
* @param kind the kind of entity key.
* @param name the name of entity key.
* @param parent the parent key to add.
* @return a key builder.
*/
public static Key.Builder builder(final String kind, final String name, final Key parent) {
return new Key.Builder().parent(parent).path(kind, name);
}
/**
* Creates a new {@code Key} builder based on an existing key.
*
* @param key the key to base this builder.
* @return a key builder.
*/
public static Key.Builder builder(final Key key) {
return new Key.Builder(key);
}
static Key.Builder builder(final com.google.datastore.v1.Key key) {
return new Key.Builder(key);
}
/**
* Return the namespace for this key.
*
* @return the namespace.
*/
public String getNamespace() {
return key.getPartitionId().getNamespaceId();
}
/**
* Return whether this key is complete or not.
*
* A complete key is a key that includes a "kind" and ("id" or "name").
*
* @return true if the key is complete.
*/
public boolean isComplete() {
if (key.getPathCount() == 0) {
return false;
}
return key.getPathList().stream().allMatch(e -> isId(e) || isName(e));
}
/**
* Return element kind of key, or null if not set.
*
* This is a shortcut for {@code Key.getPath().get(Key.getPath().size() - 1).getKind()}
*
* @return the element kind.
*/
public String getKind() {
final com.google.datastore.v1.Key.PathElement element = Iterables.getLast(key.getPathList(), null);
if (element == null) {
return null;
}
return element.getKind();
}
/**
* Return element key id, or null if not set.
*
* This is a shortcut for {@code Key.getPath().get(Key.getPath().size() - 1).getId()}
*
* @return the key id.
*/
public Long getId() {
final com.google.datastore.v1.Key.PathElement element = Iterables.getLast(key.getPathList(), null);
if (element == null) {
return null;
}
return isId(element) ? element.getId() : null;
}
/**
* Return element key name, or null if not set.
*
* This is a shortcut for {@code Key.getPath().get(Key.getPath().size() - 1).getName()}
*
* @return the key name.
*/
public String getName() {
final com.google.datastore.v1.Key.PathElement element = Iterables.getLast(key.getPathList(), null);
if (element == null) {
return null;
}
return isName(element) ? element.getName() : null;
}
/**
* Return element path that represents this key.
*
* @return a list of path elements that make up this key.
*/
public List<Element> getPath() {
return ImmutableList.copyOf(key.getPathList().stream()
.map(Element::new)
.collect(Collectors.toList()));
}
@Override
public String toString() {
return "{" + getPath().stream()
.map(Element::toString)
.collect(Collectors.joining(", ")) + "}";
}
@Override
public int hashCode() {
return key.hashCode();
}
@Override
public boolean equals(final Object obj) {
return obj == this || (obj instanceof Key && Objects.equals(key, ((Key) obj).key));
}
com.google.datastore.v1.Key getPb() {
return key;
}
com.google.datastore.v1.Key getPb(final String namespace) {
if (namespace == null) {
return key;
} else {
return com.google.datastore.v1.Key
.newBuilder(key)
.setPartitionId(
com.google.datastore.v1.PartitionId
.newBuilder().setNamespaceId(namespace)).build();
}
}
private static boolean isId(final com.google.datastore.v1.Key.PathElement element) {
return element.getIdTypeCase() == com.google.datastore.v1.Key.PathElement.IdTypeCase.ID;
}
private static boolean isName(final com.google.datastore.v1.Key.PathElement element) {
return element.getIdTypeCase() == com.google.datastore.v1.Key.PathElement.IdTypeCase.NAME;
}
}
